Insulin resistance in first-trimester pregnant women with pre-pregnant glucose tolerance and history of recurrent spontaneous abortion

Insulin resistance (IR) has been reported to play an important role in recurrent spontaneous abortion (RSA) among patients with polycystic ovary syndrome (PCOS). However, scanted materials exist regarding the independent effect of IR on RSA. The aim of this study is to investigate the status of IR in first trimester pregnant patients with normal pre-pregnant glucose tolerance and history of RSA. This two-center case-control study enrolled totally 626 first trimester pregnant women including 161 patients with a history of recurrent spontaneous abortion, who were pre-pregnantly glucose-tolerant according to oral glucose tolerance test (OGTT), and 465 women with no history of abnormal pregnancies of any kind. Clinical, biochemical and hormonal parameters were simultaneously measured in all participants. Serum beta-HCG, estradiol, progesterone, fasting plasma glucose and fasting plasma insulin levels, as well, the calculated homeostasis model assessment of insulin resistance index (HOMA-IR), fasting plasma glucose/insulin ratio(G/I) and pregnancy outcome were analyzed and compared. Serum beta-HCG and progesterone were found to be significantly lower in RSA group compared to controls. Subjects in RSA group were found to have higher HOMA-IR and lower G/I ratio than those in control group. Serum beta-HCG and progesterone were negatively correlated with HOMA-IR, and positively with G/I ratio even after adjustment for BMI. The spontaneous abortion rate within first trimester pregnancy of RSA patients was significantly higher than that in controls. In conclusion, woman with recurrent spontaneous abortion and normal pre-pregnant glucose metabolism tends to be more insulin resistant during first trimester pregnancy than healthy controls, no matter whether she has PCOS or not. Insulin resistance might be one of the direct causes that lead to recurrent abortion.

Abstract P1-13-07: Association Between Delayed Initiation of Adjuvant Chemotherapy and Survival in Breast Cancer: A Single-institution Study and A Systematic Review and Meta-analysis

Objective: Adjuvant chemotherapy (AC) improves survival among patients with operable breast cancer. However, the effect of delay in AC initiation on survival is unclear. We performed a single-institution data analysis and a systematic review and meta-analysis to determine the relationship between time to AC and survival outcomes.

Methods: PubMed, EMBASE, Cochrane Database of Systematic Reviews, and Web-of-Science databases (before March-20, 2012) were searched to identify relevant eligible studies. An additional retrospective analysis including 1,408 patients from the prospectively maintained database of Shanghai Cancer Center was performed and results were also included. Hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) from each study were converted to a regression coefficient (β) and its standard error corresponding to a continuous representation per 4-week delay of AC. Individual adjusted β were combined using a fixed-effects or random-effects model depending on heterogeneity.

Results: We included 8 eligible studies with 10 independent analytical groups involving 21,221 patients, 1 prospective observational study, 2 secondary analyses in randomized trials (4 analytical groups), and 5 hospital-/population-based retrospective studies. In our single-institution study, every 4-week delay in initiation of AC significantly decreased OS (HR = 1.38; 95% confidence interval [CI], 1.03–1.87) and DFS (HR = 1.35; 95% CI, 1.08–1.69) after adjustment for other prognostic variables. The overall meta-analysis demonstrated that a 4-week increase in time to AC was associated with a significant decrease in both OS (HR = 1.20; 95% CI, 1.03–1.39; random-effects model) and DFS (HR = 1.21; 95% CI, 1.08–1.36; fixed-effects model). One study caused a significant between-study heterogeneity for OS (p = 0.001; I2=74.1%); after excluding that single study, there was no heterogeneity (p = 0.345; I2=11.1%) and the HR was more significant (HR = 1.24; 95% CI, 1.14–1.35; P < 0.001; fixed-effects model). Our single-institution data did not fundamentally influence the positive outcomes, since the HR of OS was 1.17 (95% CI, 1.00–1.37; random-effects model) after removing our study. No evidence of publication bias was observed either in OS or in DFS.

Conclusion: The present meta-analysis suggests that longer time to AC was associated with worse survival in breast cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-13-07.

Capillary electrochromatography with novel stationary phases. 3. Retention behavior of small and large nucleic acids on octadecyl-sulfonated-silica

In this investigation, the potentials of porous and nonporous octadecyl-sulfonated-silica (ODSS) microparticles were demonstrated in the capillary electrochromatography (CEC) of small (e.g., nucleotides and dinucleotides) and large (e.g., transfer ribonucleic acids (t-RNAs)) nucleic acids. The ODSS stationary phase comprised two layers:  a hydrophilic sulfonated (permanently charged) sublayer and an octadecyl top layer. While the sublayer is to provide a relatively strong electroosmotic flow, the octadecyl top layer is to ensure the retentivity and selectivity required for the separation of the analytes. Mono-, di-, and triphosphate nucleotides were best separated when a small amount of tetrabutylammonium bromide was added to the mobile phase. The tetrabutylammonium bromide functioned as an ion-pairing agent and consequently allowed the rapid separation of 12 different nucleotides. It is believed that the dynamic complex exchange model explains the basis of retention in ion pair reversed-phase CEC. Eight different dinucleotides, which have similar mass-to-charge ratios, separated very well by CEC. These solutes exhibited similar migration times (i.e., little or no separation) in capillary zone electrophoresis (CZE). Similarly, t-RNAs that did not separate by CZE were well resolved in CEC with nonporous ODSS. This demonstrates that CEC is very suitable for the separation of solutes that have similar mass-to-charge ratios but differ in their hydrophobicity.

MicroRNA-145 inhibits the growth, invasion, metastasis and angiogenesis of neuroblastoma cells through targeting hypoxia-inducible factor 2 alpha

Recent evidence shows that hypoxia-inducible factor 2 alpha (HIF-2α) may have critical roles in the growth and progression of neuroblastoma (NB) under non-hypoxic conditions. However, the underlying mechanisms and clinical potentials of normoxic HIF-2α expression in NB still remain largely unknown. In this study, HIF-2α immunostaining was identified in 26/42 NB tissues, which was correlated with clinicopathological features. In subtotal 20 NB cases, microRNA-145 (miR-145) was downregulated and inversely correlated with HIF-2α expression. Bioinformatics analysis revealed a putative miR-145 binding site in the 3'-untranslated region (3'-UTR) of HIF-2α messenger RNA (mRNA). Overexpression or knockdown of miR-145 responsively altered both the mRNA and protein levels of HIF-2α and its downstream genes, cyclin D1, matrix metalloproteinase 14 and vascular endothelial growth factor, in normoxically cultured NB cell lines SH-SY5Y and SK-N-SH. In a luciferase reporter system, miR-145 downregulated the luciferase activity of HIF-2α 3'-UTR, and these effects were abolished by a mutation in the putative miR-145-binding site. Overexpression of miR-145 suppressed the growth, invasion, metastasis and angiogenesis of SH-SY5Y and SK-N-SH cells in vitro and in vivo, while restoration of HIF-2α expression rescued the tumor cells from miR-145-mediated defects in these biological features. Furthermore, anti-miR-145 inhibitor rescued the HIF-2α knockdown-mediated repression on the growth, migration, invasion and angiogenesis of NB cells. These data indicate that miR-145 suppresses HIF-2α expression via the binding site in the 3'-UTR under normoxic conditions, thus inhibiting the aggressiveness and angiogenesis of NB.

A biomechanical model of anther opening reveals the roles of dehydration and secondary thickening

Understanding the processes that underlie pollen release is a prime target for controlling fertility to enable selective breeding and the efficient production of hybrid crops. Pollen release requires anther opening, which involves changes in the biomechanical properties of the anther wall. In this research, we develop and use a mathematical model to understand how these biomechanical processes lead to anther opening. Our mathematical model describing the biomechanics of anther opening incorporates the bilayer structure of the mature anther wall, which comprises the outer epidermal cell layer, whose turgor pressure is related to its hydration, and the endothecial layer, whose walls contain helical secondary thickening, which resists stretching and bending. The model describes how epidermal dehydration, in association with the thickened endothecial layer, creates forces within the anther wall causing it to bend outwards, resulting in anther opening and pollen release. The model demonstrates that epidermal dehydration can drive anther opening, and suggests why endothecial secondary thickening is essential for this process (explaining the phenotypes presented in the myb26 and nst1nst2 mutants). The research hypothesizes and demonstrates a biomechanical mechanism for anther opening, which appears to be conserved in many other biological situations where tissue movement occurs.

First Report of Phomopsis Seed Decay of Soybean Caused by Phomopsis longicolla in South China

Phomopsis seed decay of soybean (Glycine max (L.) Merr.) causes poor seed quality and suppresses yield in most soybean-growing areas in the world. The disease is caused primarily by Phomopsis longicolla Hobbs. During the spring of 2010, soybean seeds without symptoms were planted in the fields but emergence was poor and the emergence rates ranged from 30 to 70% in south China. Approximately 3,000 symptomless seeds were randomly collected from seven fields at three locations in Guangzhou, Nanchang, and Wuhan. Seeds were surface disinfected with 1% sodium hypochlorite for 12 min, rinsed in sterile distilled water three to four times, and placed on 2% agar. Plates were then incubated at 26°C under 16/8-h photoperiod for 3 to 4 days. About 10 to 20% of the seeds produced white hyphae that spread rapidly and covered the whole seed. The hyphae from fungal isolates were transferred to potato dextrose agar (PDA) and incubated at 26°C in the dark. After 3 to 4 weeks, conidia were elliptical with two oil drops at both ends and hyaline (6.2 to 7.2 × 2.6 to 3.2 μm). The cultural and morphological characteristics of the isolates corresponded with the description of P. longicolla (2). Colonies on PDA were floccose, dense, and white. Stromata were large, black, and spreading. To confirm the morphological identification, the ribosomal internal transcribed spacers (ITS1-5.8S-ITS2) from three isolates were sequenced (GenBank Accession Nos. JQ899030, JQ899031, and JQ899032). BLAST analysis indicated that the isolates had 99% nucleotide sequence identity with P. longicolla (GenBank Accession Nos. AY857868.1, EF026104, and HQ130441.1). Pathogenicity tests were conducted on 2-week-old soybean seedlings (3). A mycelial plug (3 mm in diameter) from the margin of 1-week-old PDA culture of the Wuhan isolate was individually placed mycelial side down directly on the top of cut stem 1 to 2 cm above cotyledon node of the soybean seedling. PDA plugs without the fungus was used as the negative control. All seedlings were kept in a growth chamber at 26°C with 92 to 94% relative humidity. After 2 weeks, all inoculated seedlings showed browning, stem wilt, and the lesions were 0.3 to 2.0 cm long. No symptoms were observed in the control plants. P. longicolla was reisolated from the infected seedlings. The pathogenicity test was repeated three times. Soybean stem blight caused by P. longicolla has been reported in northeast China (1). To our knowledge, this is the first report of P. longicolla causing Phomopsis seed decay of soybean in south China. This report will establish a foundation for developing a program for screening germplasm for resistance to this disease in south China. References: (1) Y. L. Cui et al. Plant Pathol. 58:799, 2009. (2) T. W. Hobbs et al. Mycologia 77:535,1985. (3) S. Li et al. Plant Dis. 85:1031, 2001.

Update on World Health Organization HIV drug resistance prevention and assessment strategy: 2004-2011

The HIV drug resistance (HIVDR) prevention and assessment strategy, developed by the World Health Organization (WHO) in partnership with HIVResNet, includes monitoring of HIVDR early warning indicators, surveys to assess acquired and transmitted HIVDR, and development of an accredited HIVDR genotyping laboratory network to support survey implementation in resource-limited settings. As of June 2011, 52 countries had implemented at least 1 element of the strategy, and 27 laboratories had been accredited. As access to antiretrovirals expands under the WHO/Joint United Nations Programme on HIV/AIDS Treatment 2.0 initiative, it is essential to strengthen HIVDR surveillance efforts in the face of increasing concern about HIVDR emergence and transmission.